Patent Literature 1 discloses a conventional induction heating cooker including a heating coil having a spiral shape for heating an object. When the object is different in size from the heating coil, this conventional cooker incurs a lower heating efficiency due to increase in leakage magnetic flux or degradation in cooking performance since the heat is not distributed uniformly. This conventional induction heating cooker is thus obliged to restrict sizes of the objects.
Patent Literature 2 discloses another conventional induction heating cooker including a heating coil which can be energized partly. This cooker allows a user to select a heating area by activating a key for two objects different in size, so that the two objects can be heated efficiently. However, in the case that a small object is to be heated, a useless section of the heating coil is obliged to exist. Use of this heating coil in an induction heating cooker having multiple heating ports allows the cooker to heat different-sized objects; however, it is difficult to reserve a place for installing another heating coil, so that the heating coil can heat only a small object.
Patent Literature 1: JP2004-31247A
Patent Literature 2: JP05-47463A